Appendix A to the 2015 Supporting Statement for Subpart W

Dated September 2015 

New Subpart W Reporting Elements
Emission Source Citation Reference Rule Text 

Natural Gas Pneumatic Devices 

§98.236(b)(1)(i) The total number of devices of each type, determined according to §98.233(a)(1) and (2). 

Natural Gas Pneumatic Devices 

§98.236(b)(1)(ii)(A) The number of devices of each type reported in paragraph (b)(1)(i) of this section that are counted. 

Natural Gas Pneumatic Devices 

§98.236(b)(1)(ii)(B) The number of devices of each type reported in paragraph (b)(1)(i) of this section that are estimated (not counted)

Natural Gas Pneumatic Devices 

§98.236(b)(1)(ii)(C) If the total number of devices of each type is an estimated value determined according to § 98.233(a)(2), whether 

the calendar year is the first calendar year of reporting or the second calendar year of reporting 

Natural Gas Pneumatic Devices 

§98.236(b)(2) Estimated average number of hours in the calendar year that the natural gas pneumatic devices reported in 

paragraph (b)(1)(i) of this section were operating in the calendar year (“Tt” in Equation W-1). 

Natural Gas Pneumatic Devices 

§98.236(b)(3) Annual CO2 emissions, in metric tons CO2, for the natural gas pneumatic devices combined, calculated using 

Equation W-1 and § 98.233(a)(4), and reported in paragraph (b)(1)(i) of this section. 

Natural Gas Pneumatic Devices 

§98.236(b)(4) Annual CH4 emissions, in metric tons CH4, for the natural gas pneumatic devices combined, calculated using 

Equation W-1 and § 98.233(a)(4), and reported in paragraph (b)(1)(i) of this section 

Natural Gas Pneumatic Pump Venting 

§98.236(c)(1) Count of natural gas driven pneumatic pumps 

Natural Gas Pneumatic Pump Venting 

§98.236(c)(2) Average estimated number of hours in the calendar year the pumps were operational (“T” in Equation W-2). 

Natural Gas Pneumatic Pump Venting 

§98.236(c)(3) Annual CO2 emissions, in metric tons CO2, for all natural gas driven pneumatic pumps combined, calculated 

according to §98.233(c)(1) and (2) 

Natural Gas Pneumatic Pump Venting 

§98.236(c)(4) Annual CH4 emissions, in metric tons CH4, for all natural gas driven pneumatic pumps combined, calculated 

according to §98.233(c)(1) and (2) 

Acid Gas Removal §98.236(d)(1)(i) Unique name or ID number for acid gas removal unit. Acid Gas Removal §98.236(d)(1)(ii) Total feed rate entering the acid gas removal unit, using a meter or engineering estimate based on process 

knowledge or best available data, in million cubic feet per year. 

Acid Gas Removal §98.236(d)(1)(iii) The calculation method used to calculate CO2 emissions from the acid gas removal unit, as specified in 

§98.233(d). 

Acid Gas Removal §98.236(d)(1)(iv) Whether any CO2 emissions from the acid gas removal unit are recovered and transferred outside the facility. Acid Gas Removal §98.236(d)(1)(iv) If any CO2 emissions from the acid gas removal unit were recovered and transferred outside the facility, the annua

quantity of CO2, in metric tons CO2, that was recovered and transferred outside the facility. 

Acid Gas Removal §98.236(d)(1)(v) Annual CO2 emissions, in metric tons CO2, from the acid gas removal unit, calculated using any one of the 

calculation methods specified in §98.233(d) and as specified in §98.233(d)(10) and (11). 

Acid Gas Removal §98.236(d)(1)(vi) Name of the county that best represents the equipment supplying gas to the unit. 
Emission Source Citation Reference Rule Text 

Acid Gas Removal §98.236(d)(2)(i)(A) For each unit for which Calculation Method 1 or 2 in §98.233(d) is used, annual average volumetric fraction of 

CO2 in the vent gas exiting the acid gas removal unit.

Acid Gas Removal §98.236(d)(2)(i)(B) For each unit for which Calculation Method 1 or 2 in §98.233(d) is used, annual volume of gas vented from the 

acid gas removal unit, in cubic feet. 

Acid Gas Removal §98.236(d)(2)(ii)(A) For each unit for which Calculation Method 3 in §98.233(d) is used, which equation was used (Equation W-4A or 

W-4B). 

Acid Gas Removal §98.236(d)(2)(ii)(B) For each unit for which Calculation Method 3 in §98.233(d) is used, annual average volumetric fraction of CO2 in 

the natural gas flowing out of the acid gas removal unit, as specified in Equation W-4A or Equation W-4B. 

Acid Gas Removal §98.236(d)(2)(ii)(C) For each unit for which Calculation Method 3 in §98.233(d) is used, annual average volumetric fraction of CO2

content in natural gas flowing into the acid gas removal unit, as specified in Equation W-4A or Equation W-4B. 

Acid Gas Removal §98.236(d)(2)(ii)(D) For each unit for which Calculation Method 3 in §98.233(d) is used, the natural gas flow rate used, as specified in

Equation W-4A, reported as either total annual volume of natural gas flow into the acid gas removal unit in cubic 

feet at actual conditions; or total annual volume of natural gas flow out of the acid gas removal unit, as specified i

Equation W-4B, in cubic feet at actual conditions,.

Acid Gas Removal §98.236(d)(2)(iii)(A) For each unit for which Calculation Method 4 in §98.233(d) is used, the name of the simulation software package 

used. 

Acid Gas Removal §98.236(d)(2)(iii)(B) For each unit for which Calculation Method 4 in §98.233(d) is used, the natural gas feed temperature, in degrees 

Fahrenheit. 

Acid Gas Removal §98.236(d)(2)(iii)(C) For each unit for which Calculation Method 4 in §98.233(d) is used, the natural gas feed pressure, in pounds per 

square inch. 

Acid Gas Removal §98.236(d)(2)(iii)(D) For each unit for which Calculation Method 4 in §98.233(d) is used, the natural gas flow rate, in standard cubic 

feet per minute. 

Acid Gas Removal §98.236(d)(2)(iii)(E) For each unit for which Calculation Method 4 in §98.233(d) is used, the acid gas content of the feed natural gas, i

mole percent. 

Acid Gas Removal §98.236(d)(2)(iii)(F) For each unit for which Calculation Method 4 in §98.233(d) is used, the acid gas content of the outlet natural gas, 

in mole percent. 

Acid Gas Removal §98.236(d)(2)(iii)(G) For each unit for which Calculation Method 4 in §98.233(d) is used, the unit operating hours, excluding downtim

for maintenance or standby, in hours per year. 

Acid Gas Removal §98.236(d)(2)(iii)(H) For each unit for which Calculation Method 4 in §98.233(d) is used, the exit temperature of the natural gas, in 

degrees Fahrenheit. 

Acid Gas Removal §98.236(d)(2)(iii)(I) For each unit for which Calculation Method 4 in §98.233(d) is used, the solvent pressure, in pounds per square 

inch. 

Acid Gas Removal §98.236(d)(2)(iii)(J) For each unit for which Calculation Method 4 in §98.233(d) is used, the solvent temperature, in degrees 

Fahrenheit. 
Emission Source Citation Reference Rule Text 

Acid Gas Removal §98.236(d)(2)(iii)(K) For each unit for which Calculation Method 4 in §98.233(d) is used, the solvent circulation rate, in gallons per 

minute. 

Acid Gas Removal §98.236(d)(2)(iii)(L) For each unit for which Calculation Method 4 in §98.233(d) is used, the solvent weight, in pounds per gallon. Dehydrators §98.236(e)(1)(i) For each glycol dehydrator that has an annual average daily natural gas throughput greater than or equal to 0.4 

million standard cubic feet per day, a unique name or ID number for the dehydrator. 

Dehydrators §98.236(e)(1)(ii) Dehydrator feed natural gas flow rate, in million standard cubic feet per day, determined by engineering estimate 

based on best available data. 

Dehydrators §98.236(e)(1)(iii) Dehydrator feed natural gas water content, in pounds per million standard cubic feet. Dehydrators §98.236(e)(1)(iv) Dehydrator outlet natural gas water content, in pounds per million standard cubic feet. Dehydrators §98.236(e)(1)(v) Dehydrator absorbent circulation pump type (e.g., natural gas pneumatic, air pneumatic, or electric). Dehydrators §98.236(e)(1)(vi) Dehydrator absorbent circulation rate, in gallons per minute. Dehydrators §98.236(e)(1)(vii) Type of absorbent (e.g., triethylene glycol (TEG), diethylene glycol (DEG), or ethylene glycol (EG)). Dehydrators §98.236(e)(1)(viii) Whether stripper gas is used in dehydrator. Dehydrators §98.236(e)(1)(ix) Whether a flash tank separator is used in dehydrator. Dehydrators §98.236(e)(1)(x) Total time the dehydrator is operating, in hours. Dehydrators §98.236(e)(1)(xi) Temperature of the wet natural gas, in degrees Fahrenheit. Dehydrators §98.236(e)(1)(xii) Pressure of the wet natural gas, in pounds per square inch gauge. Dehydrators §98.236(e)(1)(xiii) Mole fraction of CH4 in wet natural gas. Dehydrators §98.236(e)(1)(xiv) Mole fraction of CO2 in wet natural gas. Dehydrators §98.236(e)(1)(xv) For each glycol dehydrator that has an annual average daily natural gas throughput greater than or equal to 0.4 

million standard cubic feet per day, whether any dehydrator emissions are vented to a vapor recovery device. 

Dehydrators §98.236(e)(1)(xvi) For each glycol dehydrator that has an annual average daily natural gas throughput greater than or equal to 0.4 

million standard cubic feet per day, whether any dehydrator emissions are vented to a flare or regenerator 

firebox/fire tubes. 

Dehydrators §98.236(e)(1)(xvi)(A) For each glycol dehydrator that has an annual average daily natural gas throughput greater than or equal to 0.4 

million standard cubic feet per day, if any emissions are vented to a flare or regenerator firebox/fire tubes, annual 

CO2 emissions, in metric tons CO2, for the dehydrator. 

Dehydrators §98.236(e)(1)(xvi)(B) For each glycol dehydrator that has an annual average daily natural gas throughput greater than or equal to 0.4 

million standard cubic feet per day, if any emissions are vented to a flare or regenerator firebox/fire tubes, annual 

CH4 emissions, in metric tons CH4, for the dehydrator. 
Emission Source Citation Reference Rule Text 

Dehydrators §98.236(e)(1)(xvi)(C) For each glycol dehydrator that has an annual average daily natural gas throughput greater than or equal to 0.4 

million standard cubic feet per day, if any emissions are vented to a flare or regenerator firebox/fire tubes, annual 

N2O emissions, in metric tons N2O, for the dehydrator. 

Dehydrators §98.236(e)(1)(xvii) For each glycol dehydrator that has an annual average daily natural gas throughput greater than or equal to 0.4 

million standard cubic feet per day, whether any dehydrator emissions are vented to the atmosphere without being 

routed to a flare or regenerator firebox. 

Dehydrators §98.236(e)(1)(xvii)(A) For each glycol dehydrator that has an annual average daily natural gas throughput greater than or equal to 0.4 

million standard cubic feet per day, if any emissions are not routed to a flare or regenerator firebox/fire tubes, 

annual CO2 emissions, in metric tons CO2, for the dehydrator when not venting to a flare or regenerator 

firebox/fire tubes. 

Dehydrators §98.236(e)(1)(xvii)(B) For each glycol dehydrator that has an annual average daily natural gas throughput greater than or equal to 0.4 

million standard cubic feet per day, if any emissions are not routed to a flare or regenerator firebox/fire tubes, 

annual CH4 emissions, in metric tons CH4, for the dehydrator when not venting to a flare or regenerator 

firebox/fire tubes. 

Dehydrators §98.236(e)(1)(xviii) For each glycol dehydrator that has an annual average daily natural gas throughput greater than or equal to 0.4 

million standard cubic feet per day, name of the county that best represents the equipment supplying gas to the 

dehydrator. 

Dehydrators §98.236(e)(2)(i) The total number of glycol dehydrators at the facility with an annual average daily natural gas throughput less tha

0.4 million standard cubic feet per day at the facility. 

Dehydrators §98.236(e)(2)(ii) For glycol dehydrators with an annual average daily natural gas throughput less than 0.4 MMscfd, the total numbe

of dehydrators at the facility that vented to a vapor recovery device. 

Dehydrators §98.236(e)(2)(iii) For glycol dehydrators with an annual average daily natural gas throughput less than 0.4 MMscfd, the number of 

dehydrators venting to a control device other than a vapor recovery device or a flare or regenerator firebox/fire 

tubes. 

Dehydrators §98.236(e)(2)(iv) For glycol dehydrators with an annual average daily natural gas throughput less than 0.4 MMscfd, whether any 

glycol dehydrator emissions are vented to a flare or regenerator firebox/fire tubes. 

Dehydrators §98.236(e)(2)(iv)(A) For glycol dehydrators with an annual average daily natural gas throughput less than 0.4 MMscfd, the total numbe

of dehydrators venting to a flare or regenerator firebox/fire tubes. 

Dehydrators §98.236(e)(2)(iv)(B) Annual CO2 emissions, in metric tons CO2, for the glycol dehydrators with an annual average daily natural gas 

throughput less than 0.4 MMscfd vented to a flare or regenerator firebox/fire tubes. 

Dehydrators §98.236(e)(2)(iv)(C) Annual CH4 emissions, in metric tons CH4, for the glycol dehydrators with an annual average daily natural gas 

throughput less than 0.4 MMscfd vented to a flare or regenerator firebox/fire tubes. 

Dehydrators §98.236(e)(2)(iv)(D) Annual N2O emissions, in metric tons N2O, for the glycol dehydrators with an annual average daily natural gas 

throughput less than 0.4 MMscfd vented to a flare or regenerator firebox/fire tubes. 
Emission Source Citation Reference Rule Text 

Dehydrators §98.236(e)(2)(v)(A) Annual CO2 emissions in metric tons CO2, for emissions from all dehydrators with an annual average daily natura

gas throughput less than 0.4 MMscfd that were not vented to a flare or regenerator firebox/fire tubes, where 

emissions are added together for all such dehydrators. 

Dehydrators §98.236(e)(2)(v)(B) Annual CH4 emissions in metric tons CH4, for emissions from all dehydrators with an annual average daily natura

gas throughput less than 0.4 MMscfd that were not vented to a flare or regenerator firebox/fire tubes, where 

emissions are added together for all such dehydrators. 

Dehydrators §98.236(e)(3)(i) For dehydrators that use desiccant, the total number of dehydrators at the facility. Dehydrators §98.236(e)(3)(i) For dehydrators that use desiccant, the total number of dehydrators venting to a vapor recovery device. Dehydrators §98.236(e)(3)(i) For dehydrators that use desiccant, the number of dehydrators venting to a control device other than a vapor 

recovery device or a flare or regenerator firebox/fire tubes. 

Dehydrators §98.236(e)(3)(i) For dehydrators that use desiccant, the total number of dehydrators venting to a flare or regenerator firebox/fire 

tubes. 

Dehydrators §98.236(e)(3)(i) Annual CO2 emissions, in metric tons CO2, for emissions from all desiccant dehydrators venting to a flare or 

regenerator firebox/fire tubes. 

Dehydrators §98.236(e)(3)(i) Annual CH4 emissions, in metric tons CH4, for emissions from all desiccant dehydrators venting to a flare or 

regenerator firebox/fire tubes. 

Dehydrators §98.236(e)(3)(i) Annual N2O emissions, in metric tons N2O, for emissions from all desiccant dehydrators venting to a flare or 

regenerator firebox/fire tubes. 

Dehydrators §98.236(e)(3)(ii) Annual CO2 emissions, in metric tons CO2, for emissions from all desiccant dehydrators that are not venting to a 

flare or regenerator firebox/fire tubes, summing for all such dehydrators. 

Dehydrators §98.236(e)(3)(iii) Annual CH4 emissions, in metric tons CH4, for emissions from all desiccant dehydrators that are not venting to a 

flare or regenerator firebox/fire tubes, summing for all such dehydrators. 

Liquids Unloading §98.236(f)(1)(ii) A list of the well ID numbers associated with each sub-basin and well tubing diameter and pressure group ID for 

which Calculation Method 1 was used to calculate natural gas emissions from well venting for liquids unloading. 

Liquids Unloading §98.236(f)(2)(i) A list of the well ID numbers associated with each sub-basin for which Calculation Method 2 or 3 was used to 

calculate natural gas emissions from well venting for liquids unloading. 

Completions and Workovers with Hydraulic Fracturing of Oil Wells 

§98.236(g) Whether the facility had any well completions or workovers with hydraulic fracturing in the calendar year. 

Completions and Workovers with Hydraulic Fracturing of Oil Wells 

§98.236(g)(1) For each completion or workover and well type combination, the sub-basin ID. 
Emission Source Citation Reference Rule Text 

Completions and Workovers with Hydraulic Fracturing - Gas and Oil Wells 

§98.236(g)(1) A list of the well ID numbers associated with each sub-basin that had completions or workovers with hydraulic 

fracturing during the calendar year. 

Completions and Workovers with Hydraulic Fracturing of Oil Wells 

§98.236(g)(2) For each sub-basin and well type combination, the well type (horizontal or vertical, gas well or oil well). 

Completions and Workovers with Hydraulic Fracturing of Oil Wells 

§98.236(g)(3) For each sub-basin and well type combination, the total number of completions or workovers. 

Completions and Workovers with Hydraulic Fracturing of Oil Wells 

§98.236(g)(4) For each sub-basin and well type combination, the calculation method used. 

Completions and Workovers with Hydraulic Fracturing of Oil Wells 

§98.236(g)(5)(i) If you used Equation W-10A to calculate annual volumetric total gas emissions for a single well in a sub-basin, th

cumulative gas flowback time, in hours, from when gas is first detected until sufficient quantities are present to enable separation (“Tp,i” in Equation W-10A). 

Completions and Workovers with Hydraulic Fracturing of Oil Wells 

§98.236(g)(5)(i) If using Equation W-10A to calculate annual volumetric total gas emissions for multiple wells in a sub-basin, the 

cumulative gas flowback time, in hours, from when gas is first detected until sufficient quantities are present to enable separation (sum of “Tp,i” values used in Equation W-10A). 

Completions and Workovers with Hydraulic Fracturing of Oil Wells 

§98.236(g)(5)(i) If you used Equation W-10A to calculate annual volumetric total gas emissions for a single well in a sub-basin, th

cumulative flowback time, in hours, after sufficient quantities are present to enable separation (“Tp,s” in Equation 

W-10A). 

Completions and Workovers with Hydraulic Fracturing of Oil Wells 

§98.236(g)(5)(i) If using Equation W-10A to calculate annual volumetric total gas emissions for multiple wells in a sub-basin, the 

cumulative flowback time, in hours, after sufficient quantities are present to enable separation (sum of “Tp,s” 

values used in Equation W-10A). 

Completions and Workovers with Hydraulic Fracturing of Oil Wells 

§98.236(g)(5)(ii) If you used Equation W-10A to calculate annual volumetric total gas emissions, the measured flowback rate, in 

standard cubic feet per hour, for each sub-basin (average of “FRs,p” values used in Equation W-12A). 
Emission Source Citation Reference Rule Text 

Completions and Workovers with Hydraulic Fracturing of Oil Wells 

§98.236(g)(5)(ii) The well ID numbers of the wells for which flowback rate is measured. 

Completions and Workovers with Hydraulic Fracturing of Oil Wells 

§98.236(g)(5)(iii)(A) If you used Equation W-12C to calculate the average gas production rate for an oil well, the gas to oil ratio for the 

well in standard cubic feet of gas per barrel of oil (“GORp” in Equation W-12C). 

Completions and Workovers with Hydraulic Fracturing of Oil Wells 

§98.236(g)(5)(iii)(B) If you used Equation W-12C to calculate the average gas production rate for an oil well, the volume of oil 

produced during the first 30 days of production after completions of each newly drilled well or well workover using hydraulic fracturing, in barrels (“Vp” in Equation W-12C). 

Completions and Workovers with Hydraulic Fracturing of Oil Wells 

§98.236(g)(6)(i) If you used Equation W-10B to calculate annual volumetric total gas emissions, the vented natural gas volume, in 

standard cubic feet, for each well in the sub-basin (“FVs,p” in Equation W-10B). 

Completions and Workovers with Hydraulic Fracturing of Oil Wells 

§98.236(g)(6)(ii) If you used Equation W-10B to calculate annual volumetric total gas emissions, the flow rate at the beginning of 

the period of time when sufficient quantities of gas are present to enable separation, in standard cubic feet per 

hour, for each well in the sub-basin (“FRp,i” in Equation W-10B). 

Completions and Workovers with Hydraulic Fracturing - Gas and Oil Wells 

§98.236(g)(6)(iii) If Equation W-10B was used to calculate annual volumetric total gas emissions, the well ID number for which 

vented natural gas volume was measured. 

Completions and Workovers with Hydraulic Fracturing of Oil Wells 

§98.236(g)(7) The well ID numbers of the wells for which flowback rate is measured. 

Completions and Workovers with Hydraulic Fracturing of Oil Wells 

§98.236(g)(8) For each sub-basin and well type combination, annual CO2 emissions, in metric tons CO2. 

Completions and Workovers with Hydraulic Fracturing of Oil Wells 

§98.236(g)(9) For each sub-basin and well type combination, annual CH4 emissions, in metric tons CH4. 
Emission Source Citation Reference Rule Text 

Completions and Workovers with Hydraulic Fracturing of Oil Wells 

§98.236(g)(10) For each sub-basin and well type combination, if the well emissions were vented to a flare, the total N2O 

emissions, in metric tons N2O. 

Completions and Workovers without Hydraulic Fracturing 

§98.236(h)(1)(i) A list of the well ID numbers associated with each sub-basin for gas well completions without hydraulic fracturin

and without flaring. 

Completions and Workovers without Hydraulic Fracturing 

§98.236(h)(2)(i) A list of the well ID numbers associated with each sub-basin for gas well completions without hydraulic fracturin

and with flaring. 

Completions and Workovers without Hydraulic Fracturing 

§98.236(h)(3)(i) A list of the well ID numbers associated with each sub-basin for gas well workovers without hydraulic fracturing 

and without flaring. 

Completions and Workovers without Hydraulic Fracturing 

§98.236(h)(4)(i) A list of the well ID numbers associated with each sub-basin for gas well workovers without hydraulic fracturing 

and with flaring. 

Blowdown Vent Stacks §98.236(i)(1)(i) If you calculated emissions from blowdown vent stacks by equipment or event type and had only one blowdown 

for a unique physical volume for an equipment or event type, the number of blowdowns in the calendar year for 

the equipment or event type for that unique physical volume (“N” from Equation W-14A or Equation W-14B). 

Blowdown Vent Stacks §98.236(i)(1)(i) If you calculated emissions from blowdown vent stacks by equipment or event type, the total number of 

blowdowns in the calendar year for the equipment or event type (the sum of equation variable “N” from Equation 

W-14A or Equation W-14B, for all unique physical volumes for the equipment or event type). 

Blowdown Vent Stacks §98.236(i)(1)(ii) If you calculated emissions from blowdown vent stacks by equipment type, annual CO2 emissions for the 

equipment or event type, in metric tons CO2. 

Blowdown Vent Stacks §98.236(i)(1)(iii) If you calculated emissions from blowdown vent stacks by equipment type, annual CH4 emissions for the 

equipment or event type, in metric tons CH4. 

Blowdown Vent Stacks §98.236(i)(2)(i) If you elect to calculate emissions from blowdown vent stacks by using a flow meter according to §98.233(i)(3), 

annual CO2 emissions from all blowdown vent stacks at the facility for which emissions were calculated using 

flow meters, in metric tons CO2 (the sum of all CO2 mass emission values calculated according to § 98.233(i)(3), 

for all flow meters). 

Blowdown Vent Stacks §98.236(i)(2)(ii) If you elect to calculate emissions from blowdown vent stacks by using a flow meter according to §98.233(i)(3), 

annual CH4 emissions from all blowdown vent stacks at the facility for which emissions were calculated using 

flow meters, in metric tons CH4, (the sum of all CH4 mass emission values calculated according to § 98.233(i)(3), 

for all flow meters). 

Blowdown Vent Stacks §98.236(i)(3)(i) For each state, annual CO2 emission in metric tons CO2. Blowdown Vent Stacks §98.236(i)(3)(ii) For each state, annual CH4 emission in metric tons CH4. 
Emission Source Citation Reference Rule Text 

Blowdown Vent Stacks §98.236(i)(3)(iii) Annual number of blowdown events for each state. Storage Tanks §98.236(j) Whether your facility sends produced oil to atmospheric tanks. Storage Tanks §98.236(j) If any of the atmospheric tanks are observed to have malfunctioning dump valves, indicate that dump valves were 

malfunctioning. 

Storage Tanks §98.236(j)(1)(i) If using Calculation Method 1 or 2, the county name. Storage Tanks §98.236(j)(1)(ii) If using Calculation Method 1 or 2, calculation method used, and name of the software package used if using 

Calculation Method 1. 

Storage Tanks §98.236(j)(1)(iii) If using Calculation Method 1 or 2, the total annual oil volume from gas-liquid separators and direct from wells o

non-separator equipment that is sent to applicable onshore production and onshore petroleum and natural gas 

gathering and boosting storage tanks, in barrels. 

Storage Tanks §98.236(j)(1)(iv) If using Calculation Method 1 or 2, the average gas-liquid separator or non-separator equipment temperature, in 

degrees Fahrenheit. 

Storage Tanks §98.236(j)(1)(v) If using Calculation Method 1 or 2, the average gas-liquid separator or non-separator equipment pressure, in 

pounds per square inch gauge. 

Storage Tanks §98.236(j)(1)(vi) If using Calculation Method 1 or 2, the average sales oil or stabilized oil API gravity, in degrees. Storage Tanks §98.236(j)(1)(vii) If using Calculation Method 1 or 2, the minimum and maximum concentration (mole fraction) of CO2 in flash gas 

from storage tanks. 

Storage Tanks §98.236(j)(1)(viii) If using Calculation Method 1 or 2, the minimum and maximum concentration (mole fraction) of CH4 in flash gas 

from storage tanks. 

Storage Tanks §98.236(j)(1)(x) If using Calculation Method 1 or 2, the number of atmospheric tanks. Storage Tanks §98.236(j)(1)(xii)(A) If using Calculation Method 1 or 2, the number of atmospheric tanks that control emissions with vapor recovery 

systems. 

Storage Tanks §98.236(j)(1)(xii)(B) If using Calculation Method 1 or 2, if any emissions from the atmospheric tanks at your facility were controlled 

with vapor recovery systems, the total CO2 mass, in metric tons CO2, that was recovered during the calendar year 

using a vapor recovery system. 

Storage Tanks §98.236(j)(1)(xii)(C) If using Calculation Method 1 or 2, if any emissions from the atmospheric tanks at your facility were controlled 

with vapor recovery systems, the total CH4 mass, in metric tons CH4, that was recovered during the calendar year 

using a vapor recovery system. 

Storage Tanks §98.236(j)(1)(xii)(D) If using Calculation Method 1 or 2, if any emissions from the atmospheric tanks at your facility were controlled 

with vapor recovery systems, annual CO2 emissions, in metric tons CO2, from atmospheric tanks equipped with 

vapor recovery systems. 

Storage Tanks §98.236(j)(1)(xii)(E) If using Calculation Method 1 or 2, if any emissions from the atmospheric tanks at your facility were controlled 

with vapor recovery systems, annual CH4 emissions, in metric tons CH4, from atmospheric tanks equipped with 

vapor recovery systems. 
Emission Source Citation Reference Rule Text 

Storage Tanks §98.236(j)(1)(xiii)(A) If using Calculation Method 1 or 2, the number of atmospheric tanks that vented gas directly to the atmosphere 

without using a vapor recovery system or without flaring. 

Storage Tanks §98.236(j)(1)(xiii)(B) If using Calculation Method 1 or 2, if any atmospheric tanks at your facility vented gas directly to the atmosphere 

without using a vapor recovery system or without flaring, annual CO2 emissions, in metric tons CO2, that resulted 

from venting gas directly to the atmosphere. 

Storage Tanks §98.236(j)(1)(xiii)(C) If using Calculation Method 1 or 2, if any atmospheric tanks at your facility vented gas directly to the atmosphere 

without using a vapor recovery system or without flaring, annual CH4 emissions, in metric tons CH4, that resulted 

from venting gas directly to the atmosphere. 

Storage Tanks §98.236(j)(1)(xiv)(A) If using Calculation Method 1 or 2, the number of atmospheric tanks that controlled emissions with flares. Storage Tanks §98.236(j)(1)(xiv)(B) If using Calculation Method 1 or 2, if you controlled emissions from any atmospheric tanks at your facility with 

one or more flares, annual CO2 emissions, in metric tons CO2, from atmospheric tanks that controlled emissions 

with one or more flares. 

Storage Tanks §98.236(j)(1)(xiv)(C) If using Calculation Method 1 or 2, if you controlled emissions from any atmospheric tanks at your facility with 

one or more flares, annual CH4 emissions, in metric tons CH4, from atmospheric tanks that controlled emissions 

with one or more flares. 

Storage Tanks §98.236(j)(1)(xiv)(D) If using Calculation Method 1 or 2, if you controlled emissions from any atmospheric tanks at your facility with 

one or more flares, annual N2O emissions, in metric tons N2O, from atmospheric tanks that controlled emissions

with one or more flares. 

Storage Tanks §98.236(j)(2)(i)(A) If using Calculation Method 3, the total annual oil/condensate throughput that is sent to all atmospheric tanks in 

the gathering and boosting facility, in barrels. 

Storage Tanks §98.236(j)(2)(i)(B) If using Calculation Method 3, an estimate of the fraction of oil/condensate throughput reported in paragraph 

(j)(2)(i)(A) sent to atmospheric tanks in the basin that controlled emissions with flares. 

Storage Tanks §98.236(j)(2)(i)(C) If using Calculation Method 3, an estimate of the fraction of oil/condensate throughput reported in paragraph 

(j)(2)(i)(A) sent to atmospheric tanks in the basin that controlled emissions with vapor recovery systems. 

Storage Tanks §98.236(j)(2)(i)(D) If using Calculation Method 3, the number of atmospheric tanks in the basin. Storage Tanks §98.236(j)(2)(ii)(A) For each county with atmospheric tanks whose emissions were calculated using Calculation Method 3 and that di

not control emissions with flares, county name. 

Storage Tanks §98.236(j)(2)(ii)(B) If using Calculation Method 3, the number of atmospheric tanks in the county that did not control emissions with 

flares, including those that have vapor recovery. 

Storage Tanks §98.236(j)(2)(ii)(C) If using Calculation Method 3, annual CO2 emissions, in metric tons CO2, from atmospheric tanks in the county 

that did not control emissions with flares, calculated using Equation W-15 and adjusted for vapor recovery, if 

applicable. 

Storage Tanks §98.236(j)(2)(ii)(D) If using Calculation Method 3, annual CH4 emissions, in metric tons CH4, from atmospheric tanks in the sub-basi

that vented gas directly to the atmosphere, calculated using Equation W-15 and adjusted for vapor recovery, if applicable. 
Emission Source Citation Reference Rule Text 

Storage Tanks §98.236(j)(2)(iii)(A) For each county with atmospheric tanks whose emissions were calculated using Calculation Method 3 and that 

controlled emissions with flares, county name. 

Storage Tanks §98.236(j)(2)(iii)(B) If using Calculation Method 3, the number of atmospheric tanks in the county that controlled emissions with 

flares. 

Storage Tanks §98.236(j)(2)(iii)(C) If using Calculation Method 3, annual CO2 emissions, in metric tons CO2, from atmospheric tanks in the county 

that controlled emissions with flares, calculated using Equation W-15. 

Storage Tanks §98.236(j)(2)(iii)(D) If using Calculation Method 3, annual CH4 emissions, in metric tons CH4, from atmospheric tanks in the county 

that controlled emissions with flares, calculated using Equation W-15. 

Storage Tanks §98.236(j)(2)(iii)(E) If using Calculation Method 3, annual N2O emissions, in metric tons N2O, from atmospheric tanks in the county 

that controlled emissions with flares. 

Storage Tanks §98.236(j)(3)(i) The total number of gas-liquid separators in the county whose liquid dump valves did not close properly during th

calendar year. 

Storage Tanks §98.236(j)(3)(ii) If using Calculation Method 1 or 2, if the gas-liquid separator liquid dump valve did not close properly on only 

one separator in a county, the total time the dump valve on the gas-liquid separator did not close properly in the calendar year, in hours (“Tn” in Equation W-16). 

Storage Tanks §98.236(j)(3)(ii) If dump valves on multiple gas-liquid separators in a county did not close properly, the total time the dump valves 

on gas-liquid separators did not close properly in the calendar year, in hours (sum of the “Tn” values used in 

Equation W-16). 

Storage Tanks §98.236(j)(3)(iii) Annual CO2 emissions, in metric tons CO2, that resulted from dump valves on gas-liquid separators in the county 

not closing properly during the calendar year, calculated using Equation W-16. 

Storage Tanks §98.236(j)(3)(iv) Annual CH4 emissions, in metric tons CH4, that resulted from the dump valves on gas-liquid separators in the 

county not closing properly during the calendar year, calculated using Equation W-16. 

Well Testing Venting and Flaring 

§98.236(l)(1)(ii) If using Equation W-17A to calculate annual volumetric natural gas emissions at actual conditions from oil wells 

and the emissions are not vented to a flare, well ID numbers for the wells tested in the calendar year. 

Well Testing Venting and Flaring 

§98.236(l)(2)(ii) If using Equation W-17A to calculate annual volumetric natural gas emissions at actual conditions from oil wells 

and the emissions are vented to a flare, well ID numbers for the wells tested in the calendar year. 

Well Testing Venting and Flaring 

§98.236(l)(3)(ii) If using Equation W-17B to calculate annual volumetric natural gas emissions at actual conditions from gas wells 

and the emissions were not vented to a flare, well ID numbers for the wells tested in the calendar year. 

Well Testing Venting and Flaring 

§98.236(l)(4)(ii) If using Equation W-17B to calculate annual volumetric natural gas emissions at actual conditions from gas wells 

and the emissions were vented to a flare, well ID numbers for the wells tested in the calendar year. 

Associated Natural Gas Venting and Flaring 

§98.236(m)(1) For each sub-basin, a list of well ID numbers for wells for which associated gas was vented or flared. 

Associated Natural Gas Venting and Flaring 

§98.236(m)(7)(i) A list of well ID numbers for wells for which associated gas was vented directly to the atmosphere without flaring
Emission Source Citation Reference Rule Text 

Associated Natural Gas Venting and Flaring 

§98.236(m)(8)(i) A list of well ID numbers for wells for which associated gas was flared. 

Flare Stacks §98.236(n)(1) Unique name or ID for the flare stack. Flare Stacks §98.236(n)(2) Indicate whether the flare stack has a continuous flow measurement device. Flare Stacks §98.236(n)(3) Indicate whether the flare stack has a continuous gas composition analyzer on feed gas to the flare. Flare Stacks §98.236(n)(4) Volume of gas sent to the flare, in standard cubic feet (“Vs” in Equations W-19 and W-20). Flare Stacks §98.236(n)(5) Fraction of the feed gas sent to an un-lit flare (“Zu” in Equation W-19). Flare Stacks §98.236(n)(6) Flare combustion efficiency, expressed as the fraction of gas combusted by a burning flare. Flare Stacks §98.236(n)(7) Mole fraction of CH4 in the feed gas to the flare (“XCH4” in Equation W-19 ). Flare Stacks §98.236(n)(8) Mole fraction of CO2 in the feed gas to the flare (“XCO2” in Equation W-20 ). Flare Stacks §98.236(n)(9) Annual CO2 emissions for each flare stack, in metric tons CO2 (refer to Equation W-20). Flare Stacks §98.236(n)(10) Annual CH4 emissions for each flare stack, in metric tons CH4 (refer to Equation W-19), unless a CEMS was used 

to measure emissions. 

Flare Stacks §98.236(n)(11) Annual N2O emissions for each flare stack, in metric tons N2O (refer to Equation W-40), unless a CEMS was used 

to measure emissions. 

Flare Stacks §98.236(n)(12) Whether a CEMS was used to measure emissions from the flare. Centrifugal Compressors §98.236(o)(5)(i) Number of centrifugal compressors that have wet seal oil degassing vents. Centrifugal Compressors §98.236(o)(5)(ii) Annual CO2 emissions, in metric tons CO2, from centrifugal compressors with wet seal oil degassing vents Centrifugal Compressors §98.236(o)(5)(iii) Annual CH4 emissions, in metric tons CH4, from centrifugal compressors with wet seal oil degassing vents. Reciprocating Compressors 

§98.236(p)(5)(i) Number of reciprocating compressors. 

Reciprocating Compressors 

§98.236(p)(5)(ii) Annual CO2 emissions, in metric tons CO2, from reciprocating compressors. 

Reciprocating Compressors 

§98.236(p)(5)(iii) Annual CH4 emissions, in metric tons CH4, from reciprocating compressors. 

Equipment Leaks by Population Counts 

§98.236(r)(1)(i) Emission source type, component type, service type, and geographic location. 

Equipment Leaks by Population Counts 

§98.236(r)(1)(ii) Total number of the emission source type at the facility (“Counte” in Equation W-32A). 

Equipment Leaks by Population Counts 

§98.236(r)(1)(iii) Average estimated time that the emission source type was operational in the calendar year, in hours (“Te” in 

Equation W-32A). 

Equipment Leaks by Population Counts 

§98.236(r)(1)(iv) Annual CO2 emissions, in metric tons CO2, for the emission source by component type, service type, and 

geographic location. 
Emission Source Citation Reference Rule Text 

Equipment Leaks by Population Counts 

§98.236(r)(1)(v) Annual CH4 emissions, in metric tons CH4, for the emission source component type, service type, and geographic 

location. 

Equipment Leaks by Population Counts 

§98.236(r)(3)(i) Calculation method used for equipment leaks. 

Equipment Leaks by Population Counts 

§98.236(r)(3)(ii)(A) An indication of whether the facility contains the major equipment type in Table W-1B. 

Equipment Leaks by Population Counts 

§98.236(r)(3)(ii)(B) For onshore petroleum and natural gas gathering and boosting, for each major equipment type, production type 

(i.e., natural gas or crude oil), and geographic location combination in Table W-1B of this subpart, if the facility 

does contain the equipment type, the count of the major equipment type. 

Combustion §98.236(z)(1)(i) For external fuel combustion units with a rated heat capacity less than or equal to 5 million Btu per hour or intern

fuel combustion units that are not compressor-drivers, with a rated heat capacity less than or equal to 1 million Bt

per hour (or the equivalent of 130 horsepower), the type of combustion unit. 

Combustion §98.236(z)(1)(ii) For each combustion unit type listed in §98.236(z)(1), the total number of combustion units. Combustion §98.236(z)(2)(i) For external fuel combustion units with a rated heat capacity greater than 5 mmBtu/hr; internal fuel combustion 

units that are not compressor-drivers, with a rated heat capacity greater than 1 million Btu per hour (or the 

equivalent of 130 horsepower); or internal fuel combustion units of any heat capacity that are compressor-drivers

the type of combustion unit. 

Combustion §98.236(z)(2)(ii) For each combustion unit type listed in §98.236(z)(2), the type of fuel combusted. Combustion §98.236(z)(2)(iii) If your facility contains: external fuel combustion units with a rated heat capacity greater than 5 mmBtu/hr; 

internal fuel combustion units that are not compressor-drivers, with a rated heat capacity greater than 1 million Bt

per hour (or the equivalent of 130 horsepower); or internal fuel combustion units of any heat capacity that are 

compressor-drivers, report for each combustion unit type and fuel type combination, the quantity of fuel 

combusted in the calendar year, in thousand standard cubic feet, gallons, or tons. 

Combustion §98.236(z)(2)(iv) For each combustion unit type listed in §98.236(z)(2), annual CO2 emissions, in metric tons CO2, calculated 

according to §98.233(z)(1) and (2). 

Combustion §98.236(z)(2)(v) For each combustion unit type listed in §98.236(z)(2), annual CH4 emissions, in metric tons CH4, calculated 

according to §98.233(z)(1) and (2). 

Combustion §98.236(z)(2)(vi) For each combustion unit type listed in §98.236(z)(2), annual N2O emissions, in metric tons N2O, calculated 

according to §98.233(z)(1) and (2). 

General §98.236(aa)(1)(ii)(D) For the onshore petroleum and natural gas production segment only, a list of the well ID numbers for producing 

wells at the end of the calendar year. 

General §98.236(aa)(1)(ii)(E) For the onshore petroleum and natural gas production segment only, a list of the well ID numbers for wells 

acquired during the calendar year. 

General §98.236(aa)(1)(ii)(F) For the onshore petroleum and natural gas production segment only, a list of the well ID numbers for wells 

divested during the calendar year. 
Emission Source Citation Reference Rule Text 

General §98.236(aa)(1)(ii)(G) For the onshore petroleum and natural gas production segment only, a list of the well ID numbers for wells 

completed during the calendar year. 

General §98.236(aa)(1)(ii)(H) For the onshore petroleum and natural gas production segment only, a list of the well ID numbers for wells 

permanently taken out of production (i.e., plugged and abandoned) during the calendar year. 

General §98.236(aa)(10)(i) The quantity of gas received by the gathering and boosting facility in the calendar year, in thousand standard cubi

feet. 

General §98.236(aa)(10)(ii) The quantity of gas transported to a natural gas processing facility, a natural gas transmission pipeline, a natural 

gas distribution pipeline, or another gathering and boosting facility in the calendar year, in thousand standard cub

feet. 

General §98.236(aa)(10)(iii) The quantity of all hydrocarbon liquids received by the gathering and boosting facility in the calendar year, in 

barrels. 

General §98.236(aa)(10)(iv) The quantity of all hydrocarbon liquids transported to a natural gas processing facility, a natural gas transmission 

pipeline, a natural gas distribution pipeline, or another gathering and boosting facility in the calendar year, in 

barrels. 

Natural gas transmission pipelines 

§98.236(aa)(11)(i) The quantity of natural gas received at all custody transfer stations in the calendar year, in thousand standard cubi

feet. This value may include meter corrections, but only for the calendar year covered by the annual report. 

Natural gas transmission pipelines 

§98.236(aa)(11)(ii) The quantity of natural gas withdrawn from in-system storage in the calendar year, in thousand standard cubic fee

Natural gas transmission pipelines 

§98.236(aa)(11)(iii) The quantity of natural gas added to in-system storage in the calendar year, in thousand standard cubic feet. 

Natural gas transmission pipelines 

§98.236(aa)(11)(iv) The quantity of natural gas transferred to third parties such as LDCs or other transmission pipelines, in thousand 

standard cubic feet. 

Natural gas transmission pipelines 

§98.236(aa)(11)(v) The quantity of natural gas consumed by the transmission pipeline facility for operational purposes, in thousand 

standard cubic feet. 

Natural gas transmission pipelines 

§98.236(aa)(11)(vi) The miles of transmission pipeline for each state in the facility.